The installation of curtain wall modules (CWMs) is a risky activity carried out in the heights and often under unfavorable weather conditions. CWMs are heavy prefabricated walls that are lifted normally with bindings and cranes. High stability is needed while positioning in order not to damage the fragile CWMs. Moreover, this activity requires high precision while positioning brackets, the modules, and for that reason, intensive survey and marking are necessary. In order to avoid such inconveniences, there were experiences to install façade modules in automatic mode using robotic devices. In the research project HEPHAESTUS, a novel system has been developed in order to install CWMs automatically. The system consists of two sub-systems: a cable driven parallel robot (CDPR) and a set of robotic tools named as Modular End Effector (MEE). The platform of the CDPR hosts the MEE. This MEE performs the necessary tasks of installing the curtain wall modules. There are two main tasks that the CDPR and MEE need to achieve: first is the fixation of the brackets onto the concrete slab, and second is the picking and placing of the CWMs onto the brackets. The first integration of the aforementioned system was carried out in a controlled environment that resembled a building structure. The results of this first test show that there are minor deviations when positioning the CDPR platform. In future steps, the deviations will be compensated by the tools of the MEE and the installation of the CWM will be carried out with the required accuracy automatically.
The present paper proposes equivalent stiffness and energy dissipation properties of reinforced concrete hollow bridge piers to be used in the context of response spectrum performance based assessment and design. The work is carried out by performing parametric numerical analysis using a 2D fibre model calibrated against experimental results and by varying the longitudinal steel reinforcement ratio, height over width ratio, normalised axial force, level of confinement and concrete class of a rectangular hollow section reinforced with Tempcore B500C steel. The results of the analysis are given in the form of charts and closed form expressions for the yield curvature and moment, ultimate ductility, post yielding stiffness ratio and energy dissipated of the section, and are translated to the member level through the plastic hinge length approach. Likewise, the parameters of a Takeda model derived from the parametric analysis are given for use in nonlinear time history analysis.Keywords Bridge pier hollow section · Performance based design · Equivalent stiffness · Equivalent damping · Plastic hinge length · Takeda model Abbreviations DBD Displacement based design PsD Pseudo-dynamic RC Reinforced concrete
The multiple advantages presented by Fiber Bragg Grating (FBG) sensors, if compared with other sensor typologies, are strengthening the development of Structural Health Monitoring (SHM) systems based on this technology. The application fields include a wide variety of industries, highlighting those where safety and reliability are key aspects, as aerospace and civil. In this paper, two examples are shown where FBG networks have been implemented for monitoring of structural tests, including composite aircraft cockpit during pressurization tests, and a concrete/CFRP pillar subjected to compression tests.
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